a. Field of the Invention
The present invention relates to a heat sensitive recording material, and more particularly, to a heat sensitive recording material having excellent transparency and anti-scratch property.
b. Description of the Prior Art
A heat-sensitive recording method has many advantages in that no particular developing step is required, (2) if paper is used as a support, the recording material can have a quality akin to that of plain paper, (3) handling of the recording material used is easy, (4) the images recorded have high color density, (5) this method can be effected using a simple and cheap apparatus and (6) no noise is caused during recording. Therefore, heat-sensitive recording materials have recently enjoyed a markedly increasing demand, particularly for use with a facsimile or printer, and have come to be used for many purposes.
From this situation, it has been desired to devise transparent heat-sensitive recording materials which enable direct recording with a thermal head in order to adapt them for multicolor development, or to make them usable for an overhead projector (hereafter abbreviated as OHP).
To satisfy the above desire, recently, a heat sensitive recording material having an excellent transparency was proposed which comprises a support having thereon a heat sensitive layer said heat sensitive layer being formed by coating a solution including an emulsified dispersion obtained by dispersing microcapsules containing colorless or light colored electron donating dye precursor and color developer dissolved in an organic solvent slightly soluble or insoluble in water then drying it.
On the otherhand, generally, bad chance such as being scratched is increased when a heat sensitive recording material is used for OHP or multi color recording, then a protective layer should be provided on the heat sensitive layer in practice.
However, the tranceparency of before mentioned heat sensitive layer is reduced when a protective layer is provided on the heat sensitive layer.
Therefore, more improvement on the transparency has been requested to the protective layer in order to make the heat sensitive recording material usable for OHP or to reproduce a faithful color in multi coloring.